The company wants to dig deep into beaches and remove oil buried since a BP well blew out on April 20, 2010, leading to the nation's largest offshore spill.

But digging deep can bring its own problems — it can be harmful to creatures that live on beaches or feed on them and it also may lead to erosion by loosening up sand. Erosion is a constant worry in Louisiana because the state is losing land at an alarming rate.

Mike Utsler, the president of BP's Gulf Coast Restoration Organization, said Tuesday the company has asked the Coast Guard and state and local officials for permission to do the "deep-cleaning."

Transocean Ltd. and the Justice Department have discussed a $1.5 billion settlement that would resolve federal civil and criminal claims against the company over its role in the deadly 2010 rig explosion that spawned the nation's worst offshore oil spill.

But Switzerland-based Transocean Ltd. said in a regulatory filing Monday that a "number of issues," including the possible time period for payment, must be resolved before a deal can be completed.